Many image processing tasks are simplified if the image can be segmented into spatial regions where a region has some unifying property. For example a particular region may correspond with the extent of a portrayed object. Examples of processes that can benefit from image segmentation include: data compression, where similar coding decisions can be applied over a particular segment; motion compensated processing, where the same motion vector can be applied to a particular region; and, re-framing, where there is a need to ensure that a particular segment remains within the frame.
Known methods of image segmentation include the detection of edges by means of spatial filtering of the image and then bridging any gaps in the detected edges to form a segment boundary. These methods can be complex and detected edges may not correspond to the edges of image regions.